Study of Small Molecule Organic Solar Cells Performance Based on Boron Subphthalocyanine Chloride and C60

The small molecule organic solar cells based on boron subphthalocyanine chloride (SubPc) and C60 by varying the SubPc layer thickness from 3 nm to 21 nm were fabricated. The maximum power conversion efficiency (PCE) of 1.47% was obtained at the 9 nm SubPc layer under 100 mW/cm2 AM1.5G illumination, which is attributed to reach the optimal balance between the light absorption efficiency and the carrier collection efficiency in the device. To increase the open-circuit voltage (Voc) of device, the molybdenum oxide (MoO3) and poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) were inserted between the indium tin oxide and the SubPc layer, respectively. Finally, the Voc of device increased from 0.46 V to 1 V by using MoO3 buffer layer, resulting in the fact that the PCE of device increased from 1.47% to 2.52%.